Moving walkways which have a variable speed over their length in order to be able to bridge large distances in a relatively short time are known for the purpose of conveying persons. In order to make it possible for the persons to be conveyed to easily enter and exit, the ends of the moving walkway are moved at a first, lower speed. After the entry region, the moving walkway usually formed from individual moving walkway plates accelerates to a second, higher transport speed before the deceleration to a lower speed, for example the first speed, is carried out in an exit region. In practice, a speed of 0.6 m/s, for example, may be provided for the entry and exit regions, whereas the second, higher speed is 2 m/s.
In order to enable the described change in the speed along the length of the moving walkway, the moving walkway plates must be able to be moved in a telescope-like manner with respect to one another. In order to enable driving at different speeds and an acceleration, it is known practice to drive the moving walkway plates in the entry and exit regions with a worm which has a variable pitch. Such a worm is then used to accelerate the moving walkway plates to the second speed and to decelerate them from the second speed, a chain which moves at the higher, second speed being provided between the worms.
Mechanically driven moving walkways with a variable speed are known from EP 1 253 101 B1, EP 1 300 359 B1, EP 1 582 494 B1, EP 1 939 127 B1, EP 1 939 128 A2, EP 1 939 129 B1 and EP 1 939 130 B1. Even if the moving walkways described have proved themselves in practice, there is a need to simplify the design. In particular, the mechanical drive necessitates a relatively complicated configuration, in which case an amount of maintenance which is conventional for mechanical drives also arises.
EP 1 258 447 B1 and EP 1 502 891 B1 disclose drive arrangements and, in particular, moving walkways in which individual tread bodies in the form of moving walkway steps or moving walkway plates are provided with their own electromotive drive. This initially results in the advantage that it is possible to dispense with a central drive train in the form of a circulating chain or the like. Furthermore, EP 1 258 447 B1 also proposes moving the moving walkway plates with an increased speed on a return transport path, with the result that the number of moving walkway plates can be reduced overall. However, equipping the moving walkway plates with their own electric motor is associated with a considerable amount of effort overall.
EP 1 845 428 A2 discloses an electromotive linear drive arrangement in which the secondary parts are each equipped with two permanent magnets which interact with different primary parts or primary sections. The two magnets with the respectively assigned primary part form two linear motors which are separate from one another. The movement is therefore transferred from one linear motor to the other at transition points. The linear motors formed in this manner are only alternately active. A sensor can be used to determine the position of the pallet equipped with the two permanent magnets.
EP 2 161 826 B1 discloses a transfer apparatus having dynamically changeable drive regions. The primary part is subdivided into a plurality of regions each with a secondary part. The region boundaries of this division are dynamically concomitantly moved with the secondary parts, the individual secondary parts being able to be moved with a predefined movement profile. Successive secondary parts can be moved in this case in an exactly identical manner or else differently with respect to one another.